There is a grim medical term, Isadora Duncan syndrome, for injuries when neckwear tangles in machinery, named for one of the most bizarre and tragic deaths of the 20th century. Yet the woman behind it is universally recognized as the mother of modern dance, a life devoted to untethered freedom and stalked by relentless tragedy.

From impoverished San Francisco to the opulent drawing rooms of Europe, Duncan shattered corseted classical ballet by dancing barefoot in Greek tunics, insisting all movement originate from the solar plexus. She founded utopian schools, endured the drowning deaths of her children, and died when her flowing red shawl caught in a car wheel.

• Her chaotic San Francisco childhood and scandal-forged independence
• The biomechanical philosophy of movement flowing from the body's center
• Winning over a ...